In light of just-passed federal legislation, a chemical industry group is asking the Environmental Protection Agency to change course on its assessment of the most potent form of dioxin, a pollutant that causes cancer and is linked to reproductive problems. Such a move by the agency could drag out completion of the assessment, which has been underway for 20 years.

The American Chemistry Council, a trade association, asked EPA in a Dec. 20 letter to delay release of the hazard assessment for 2,3,7,8-dibenzo-p-dioxin (TCDD). Before it issues the document, ACC says, the agency should explain how the document hews to recent recommendations by the National Research Council.

In April, NRC included a number of recommendations for EPA to improve its assessments of chemicals as part of a report criticizing the agency’s draft document on the hazards of formaldehyde (C&EN, April 18, page 10). EPA began implementing those recommendations in July (C&EN, July 18, page 10).

Now, language in the final fiscal 2012 appropriations spending measure (H.R. 2055) that Congress passed last week instructs EPA to document how the NRC recommendations have been implemented for each draft chemical assessment it releases in 2012. The legislation also requires the agency to provide an explanation for any recommendation it does not follow. President Barack Obama is expected to sign the spending measure into law soon.

The letter from ACC President and CEO Calvin M. Dooley asks agency Administrator Lisa P. Jackson to reverse course on an EPA strategy, unveiled in August, to get the long-pending document finished (C&EN, Sept. 5, page 15). The agency announced it would issue the TCDD assessment in two parts.

One will analyze the adverse noncancer health effects, such as reproductive problems, from exposure to TCDD. This part is nearly finished, and EPA has said it would release this section by the end of January 2012.

The second, more scientifically complicated part of the assessment will examine the cancer hazards of TCDD exposure and will be released “as quickly as possible,” the agency has said.

EPA’s plan to finalize the TCDD document in stages is counter to NRC’s recommendation that the agency’s chemical assessments evaluate all relevant health endpoints, Dooley’s letter argues. Bifurcating the assessment could prompt the agency to revise cleanup guidance based on TCDD’s noncancer effects—then revise them again later based on carcinogenicity concerns, explains association spokesman Scott Jensen.

“It is incumbent on EPA to fully explain” how the final TCDD assessment comports with the NRC recommendations, Dooley writes. Although the legislation specifies that this provision applies to releases of draft assessments, ACC believes this provision should apply to all such documents that are now in draft form, including the TCDD assessment, Jensen says.

But there’s nothing wrong with the agency making part of the TCDD hazard information available to the public, says Stephen Lester, science director for the activist group Center for Health, Environment & Justice “ACC is just scared that this information will become finalized and people can then utilize it,” he tells C&EN.

When finalized, the assessment will guide federal and state regulators in setting cleanup requirements for areas polluted with TCDD, polychlorinated biphenyls (PCBs), or related chlorinated and brominated dioxins and furans.

Thanks--this is an important story. Here's an update with more on the National Chicken Council's and other producers' worries about the dioxin limits--provides a video, too, ranking foods by dioxin contamination (see "Dioxins in the Food Supply" link): http://nutritionfacts.org/?p=5185